1. Field of the Invention
This invention relates to a method for the preparation of a mixture of a dithiodibenzoate, a dithiocarbonate, and a trithiocarbonate. These compounds are useful as intermediates for the production of saccharin or saccharin salts* and can undergo hydrolysis followed by oxidation to produce 2,2'-dithiodibenzoic acid, useful as an intermediate in the production of compounds such as 1,2-benzisothiazoline-3-one** which has utility as a fungicide and bactericide. FNT *See, for example, U.S. Pat. Nos. 2,667,503 and 3,325,475. FNT **See, for example, British Pat. Nos. 918,869 and 884,541.
2. Description of the Prior Art
The prior art describes methods of diazotizing an aminobenzoic acid ester or thio ester, and reacting the resulting diazonium salt with such compounds as disulfide salts, xanthate salts and trithiocarbonate salts, to produce organic xanthates, di-and trithiocarbonates, and alkylene-dixanthates.* FNT *See, for example, U.S. Pat. No. 3,652,632.
The reaction of diazonium compounds with CS.sub.2 has not been extensively studied. A few academic works have mentioned CS.sub.2 in connection with attempts to explain the mechanism of decomposition and some reactions of aromatic diazonium compounds.** Also, the reaction of arylradicals (which had been produced from corresponding aryldiazonium fluoroborates by the action of NaI) with CS.sub.2 to produce various diaryldisulfides has been discussed.*** FNT **See, for example, Hurtley and Smiles, J. Chem. Soc., (1926) pp. 1821-28, and Hodgson, J. Chem. Soc., (1948) pp. 348-54. FNT ***Reactivity of Carbon Disulfide with Aryl Radicals, J. Org. Chem., 41, (1976) pp. 2639-40.